From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 979B3C3A589 for ; Thu, 15 Aug 2019 16:59:27 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6DEE0206C1 for ; Thu, 15 Aug 2019 16:59:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DEE0206C1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44562 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyJ5y-000518-L8 for qemu-devel@archiver.kernel.org; Thu, 15 Aug 2019 12:59:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47474) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyIjw-0002z2-4w for qemu-devel@nongnu.org; Thu, 15 Aug 2019 12:36:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyIjs-0003Oj-4U for qemu-devel@nongnu.org; Thu, 15 Aug 2019 12:36:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39416) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hyIjr-0003NN-TP for qemu-devel@nongnu.org; Thu, 15 Aug 2019 12:36:36 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 31F0F3001D30; Thu, 15 Aug 2019 16:36:35 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-19.ams2.redhat.com [10.36.117.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC9A6BAAC; Thu, 15 Aug 2019 16:36:33 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org Date: Thu, 15 Aug 2019 17:34:55 +0100 Message-Id: <20190815163504.18937-25-dgilbert@redhat.com> In-Reply-To: <20190815163504.18937-1-dgilbert@redhat.com> References: <20190815163504.18937-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 15 Aug 2019 16:36:35 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 24/33] migration: always initialise ram_counters for a new migration X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quintela@redhat.com, yury-kotov@yandex-team.ru, richardw.yang@linux.intel.com, marcandre.lureau@redhat.com, ivanren@tencent.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Ivan Ren This patch fix a multifd migration bug in migration speed calculation, th= is problem can be reproduced as follows: 1. start a vm and give a heavy memory write stress to prevent the vm be successfully migrated to destination 2. begin a migration with multifd 3. migrate for a long time [actually, this can be measured by transferred= bytes] 4. migrate cancel 5. begin a new migration with multifd, the migration will directly run in= to migration_completion phase Reason as follows: Migration update bandwidth and s->threshold_size in function migration_update_counters after BUFFER_DELAY time: current_bytes =3D migration_total_bytes(s); transferred =3D current_bytes - s->iteration_initial_bytes; time_spent =3D current_time - s->iteration_start_time; bandwidth =3D (double)transferred / time_spent; s->threshold_size =3D bandwidth * s->parameters.downtime_limit; In multifd migration, migration_total_bytes function return qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes. s->iteration_initial_bytes will be initialized to 0 at every new migratio= n, but ram_counters is a global variable, and history migration data will be accumulated. So if the ram_counters.multifd_bytes is big enough, it may l= ead pending_size >=3D s->threshold_size become false in migration_iteration_r= un after the first migration_update_counters. Signed-off-by: Ivan Ren Reviewed-by: Juan Quintela Reviewed-by: Wei Yang Suggested-by: Wei Yang Message-Id: <1564741121-1840-1-git-send-email-ivanren@tencent.com> Signed-off-by: Dr. David Alan Gilbert --- migration/migration.c | 25 +++++++++++++++++++------ migration/savevm.c | 1 + 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 12b8e5dbe5..c49e9dc035 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1911,6 +1911,11 @@ static bool migrate_prepare(MigrationState *s, boo= l blk, bool blk_inc, } =20 migrate_init(s); + /* + * set ram_counters memory to zero for a + * new migration + */ + memset(&ram_counters, 0, sizeof(ram_counters)); =20 return true; } @@ -3034,6 +3039,17 @@ static void migration_calculate_complete(Migration= State *s) } } =20 +static void update_iteration_initial_status(MigrationState *s) +{ + /* + * Update these three fields at the same time to avoid mismatch info= lead + * wrong speed calculation. + */ + s->iteration_start_time =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + s->iteration_initial_bytes =3D migration_total_bytes(s); + s->iteration_initial_pages =3D ram_get_total_transferred_pages(); +} + static void migration_update_counters(MigrationState *s, int64_t current_time) { @@ -3069,9 +3085,7 @@ static void migration_update_counters(MigrationStat= e *s, =20 qemu_file_reset_rate_limit(s->to_dst_file); =20 - s->iteration_start_time =3D current_time; - s->iteration_initial_bytes =3D current_bytes; - s->iteration_initial_pages =3D ram_get_total_transferred_pages(); + update_iteration_initial_status(s); =20 trace_migrate_transferred(transferred, time_spent, bandwidth, s->threshold_size); @@ -3194,7 +3208,7 @@ static void *migration_thread(void *opaque) rcu_register_thread(); =20 object_ref(OBJECT(s)); - s->iteration_start_time =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + update_iteration_initial_status(s); =20 qemu_savevm_state_header(s->to_dst_file); =20 @@ -3259,8 +3273,7 @@ static void *migration_thread(void *opaque) * the local variables. This is important to avoid * breaking transferred_bytes and bandwidth calculation */ - s->iteration_start_time =3D qemu_clock_get_ms(QEMU_CLOCK_REA= LTIME); - s->iteration_initial_bytes =3D 0; + update_iteration_initial_status(s); } =20 current_time =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); diff --git a/migration/savevm.c b/migration/savevm.c index 412768216c..1ac15301ad 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1456,6 +1456,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **e= rrp) } =20 migrate_init(ms); + memset(&ram_counters, 0, sizeof(ram_counters)); ms->to_dst_file =3D f; =20 qemu_mutex_unlock_iothread(); --=20 2.21.0